Semiconductor components are mounted on a printed wiring board, usually on one side thereof. Cooling of such printed wiring boards with their associated semiconductor devices is required to keep the semiconductor devices below their critical temperature. The most common way of cooling such circuit card assemblies is by blowing air thereover. Of course, such air cooling has definite limits as to the amount of heat that can be removed, especially when the circuit card assembly is densely packed with electronic components or applied in an environment where direct external air impingement to the circuit card is undesirable or forbidden. Furthermore, such circuit card assemblies must be spaced so that adequate air can flow therebetween for cooling. Conductive cooling has been attempted by fitting thermal mounting plates directly against the semiconductor device packages, usually between the components and the circuit card. Such thermal mounting plates are difficult to construct and often have poor thermal pathways due to long, thin thermal conductive sections. The thickness of the material is limited due to component lead lengths, and the thickness of the printed wiring board. Attempts to cool the semiconductor packages on the circuit card assembly by contact with the packages themselves have the difficulty of requiring individual fitting of the cooler, due to the different configurations and positions of the packages. Furthermore, a cooler on the component side of the device must be removed before the circuit card assembly can be serviced. There is still need for a conduction cooling structure and method of making the structure by which a group of various sized electronic packaged devices assembled on a circuit card can be conductively cooled.
The uniqueness of this invention is that it provides a structure and method for cooling circuit card assemblies, that were designed for direct air impingement convection cooling, by means of conduction without redesigning the circuit card. It provides a cooler which can be applied to any circuit card assembly of the same size without reference to the positions and types of components thereon. The cooler will cool the electronic components conductively in a manner equal to or superior to forced convection cooling.